As a handicapper who uses current circumstances to construct scenarios about the future, I know full well how unpredictable tomorrow is. In fact, I repeatedly warn readers and listeners that unexpected events can change our lives and our politics overnight.

In the political sphere, the standing of President Barack Obama is a case in point. Obama was elected on a surge of optimism that he could bring about “change,” revitalize the U.S. economy and enhance the nation’s status around the world.

By the spring of 2009, more and more Americans were telling pollsters that the country was headed in the right direction, and the president’s aggressive response to crises in the financial sector and automobile industry gave way to predictions that an economic recovery was not too distant.

America’s reputation around the world improved as the new president traveled the globe, bringing his personal magic with him. A Democratic special election victory in the spring of 2009 in upstate New York seemed to foreshadow additional electoral problems for the GOP.

But, as the late, great Broadway actor Zero Mostel might have said, “A funny thing happened on the way to the midterms.”

Almost all of the president’s initiatives ran into trouble, even with huge majorities in the House and Senate, and the jobs recovery never occurred. If the situation in Iraq improved, the war in Afghanistan — which during the 2008 campaign then-candidate Obama cited as the more important struggle against terrorism — took a turn for the worse.

This president, like Presidents Jimmy Carter, George H.W. Bush and George W. Bush before him, learned the lesson that every investment fund manager knows: Evidence of past performance doesn’t guarantee future results.

And now the president, who is expected to raise close to $1 billion for his re-election campaign, who faces a Republican field widely mocked as undistinguished and who can rely on the same team of brilliant political gurus who masterminded his 2008 victory, suddenly finds his re-election in doubt.

President Obama, meet your baseball counterpart, the Boston Red Sox.

The Red Sox may still win the World Series because the playoff system now allows “wild card” teams to make the playoffs and because anything can happen in a short series. But that shouldn’t erase the stunning underperformance of the Red Sox, who were picked by almost everyone to win the American League pennant.

With a team including newly acquired star first baseman Adrian Gonzalez, free agent outfielder Carl Crawford, Kevin Youkilis, Dustin Pedroia, Jacoby Ellsbury and David Ortiz, plus starting pitchers Jon Lester and Josh Beckett and a fabulous bullpen, how could Red Sox Nation not be rewarded with a pennant after another dominant performance during the regular season?

Tampa Bay might be good, but after losing Crawford to the Red Sox and with an uncertain pitching staff and an even iffier bullpen, they obviously couldn’t compete.

The Yankees, we heard, are nothing but an aging team with only a single established starting pitcher, a closer over 40, an aging shortstop with no range and a deteriorating bat, a catcher who can’t catch anymore and a roster that didn’t make a major acquisition over the summer except for a setup man.

Of a dozen Sports Illustrated “experts” who made predictions in the spring, only one, Albert Chen, picked the Yankees. The other 11 selected the Red Sox to win the American League East. (Chen was one of two experts to select the Detroit Tigers’ Justin Verlander for the league’s Cy Young, an award that Verlander certainly deserves to win.)

Over at ESPN, the highly regarded sports network, 45 “experts” made their predictions, and all 45 — that’s right, each and every one — picked the Red Sox to win the A.L. East. Included in that list are experts Tim Kurkjian and Jayson Stark, among the savviest observers of baseball.

CBS.com’s experts did a bit better, I suppose. Only seven of eight picked the Red Sox, with one selecting the Yankees.

Fox’s Ken Rosenthal picked the Red Sox to win the pennant, as did all three of the Baltimore Sun’s baseball experts, all six of the Boston Globe’s columnists (including the always opinionated if rarely correct Bob Ryan) and all three of the handicappers at the New York Times.

Make no mistake about it: The Red Sox deserved to be picked.

I’d like to think that the Red Sox’s disappointing performance is some sort of divine punishment for the team’s history of racism or maybe the arrogance of a city that calls itself the “Hub” (of the universe, that is) and treats everything beyond Route 128 as territory not yet civilized.

Conservatives might see it as a judgment for the state’s partisan bent and its support for liberal politicians, except for that fact that New York City’s politics aren’t much different.

Whatever the reason, the Red Sox’s inability to win the American League East is nothing short of stunning. Yes, the team had significant injuries, but so did the Yankees (Alex Rodriguez, Phil Hughes, Joba Chamberlain and Rafael Soriano, to mention the most obvious.)

Boston will no doubt take the winter as an opportunity to restock. And the team could conceivably win the World Series this year and for the rest of the decade, even with this disappointing regular season.

As for me, I’ll simply smile about the season the underdog Yankees have had and relish yet another tremendous summer by Derek Jeter, who is hitting a robust .295 as the season comes to a close.

Picking baseball teams, much like predicting the political future, is a humbling business.